Authors : Esmat Khaleqsefat and Reza Malekzadeh-Viayeh
Abstract: The seasonal patterns of rotifer community structure in response to temporal fluctuations in environmental variables were investigated in two water bodies located in Northwest Iran. Sampling was carried out during October 2007 to November 2008. In total, 45 rotifer species were identified from the two studied sites. In each site, rotifer species diversity differed seasonally. Temporal patterns observed innon-metric Multidimensional Scaling (nMDS) ordinationsrevealed separation of Summer from other seasons due to different diversity and density of the rotifer assemblages. Analysis of Variance (ANOVA) also showed significant difference in the rotifer diversity and abundance among seasons (F = 4.7, p<0.05). Rotifer species diversity was highly correlatedwith the level of dissolved oxygen and pH in the reservoir Cheshmehgul (r = 0.92 and 0.63, respectively, p<0.001). However, analysis of the accumulated data of both water bodies revealed that a significant Spearman=s correlation coefficient existed between salinity and water temperature and the abundance of the rotifers (r = 0.54, p<0.001). Canonical Correspondence Analysis (CCA) identified dissolved oxygen and electrical conductivity to be the main environmental factors shaping the rotifer assemblages. According to this study, seasonal variations in environmental factors can influence structure of rotifer communities even in distinct, unrelated ecosystems.
Esmat Khaleqsefat and Reza Malekzadeh-Viayeh, 2013. Effect of Season and Environmental Variables on Rotifer Community Structure: Evidence from Two Selected Freshwaters in Northwest Iran. Research Journal of Animal Sciences, 7: 34-41.